Osteogenesis imperfecta (OI) literally means "imperfectly formed bone." People with
osteogenesis imperfecta have a genetic defect that impairs the body's ability to make
strong bones.

OI is a relatively rare condition. Some people have a more severe form of the disorder
in which their bones break easily. They may break hundreds of bones during their lives.
Many people, however, have a milder form of OI, and go through life with few fractures.

Cause

In people with osteogenesis imperfecta, one of the genes that tells the body how to
make a specific protein does not function. This protein (type I collagen) is a major
component of the connective tissues in bones. Type I collagen is also important in
forming ligaments, teeth, and the white outer tissue of the eyeballs (sclera).

As a result of the defective gene, not enough type I collagen is produced, or the
collagen that is produced is of poor quality. In either case, the result is fragile
bones that break easily but can heal at a normal rate.

In most cases of OI, children inherit the defective gene from one of their parents.
But, the child's symptoms and the degree of disability can be very different from
that of the parent.

In some children, neither parent has osteogenesis imperfecta. In these cases, the
genetic defect is a spontaneous mutation (change) in the gene, and it stops functioning
correctly.

There are different types of osteogenesis imperfecta with symptoms that range from
mild to severe. Each person with the condition may have a different combination of
symptoms. All people with OI, however, have weaker bones.

This 16-year-old boy has bone deformities in both his shinbones that have not yet
been straightened with surgery.

Courtesy of Texas Scottish Rite Hospital for Children.

In many children with OI, the number of times their bones fracture decreases significantly
as they mature. However, osteogenesis imperfecta may become active again after menopause
in women or after the age of 60 in men.

Scoliosis, or curvature of the spine, is a problem for many children with osteogenesis
imperfecta.

There are several types of OI and they vary in severity and characteristics. As scientists
have discovered new genetic problems causing OI, new types of the disorder have been
recognized. All types of the disorder, however, have symptoms and severity that fall
somewhere within the range of the first four types recognized. These four types are
described below.

Type I

Type I osteogenesis imperfecta is the most common and mildest type of this disease.
While the structure of the collagen is normal, there is less collagen than there should
be. There is little or no bone deformity, although the bones are fragile and easily
broken. The effects of OI may extend to the teeth, making them prone to cavities and
cracking. The whites of the eyes may have a blue, purple, or gray tint.

Type II

Type II osteogenesis imperfecta is the most severe form of the disease. The collagen
does not form properly. Bones may break even while the fetus is in the womb. Many
infants with type II osteogenesis imperfecta do not survive.

Type III

Type III osteogenesis imperfecta also has improperly formed collagen and often severe
bone deformities, plus additional complications. The infant is often born with fractures.
The whites of the eyes may be white, blue, purple, or gray. People with type III osteogenesis
imperfecta are generally shorter than average. They may have spinal deformities, respiratory
complications, and brittle teeth.

Type IV

Type IV osteogenesis imperfecta is moderately severe, with improperly formed collagen.
Bones fracture easily, but the whites of the eyes are normal. Some people with type
IV osteogenesis imperfecta may be shorter than average and may have brittle teeth.
Bone deformities are mild to moderate.

In many cases, broken bones that occur with little or no force are the first sign
of osteogenesis imperfecta, and will cause your doctor to suspect the condition.

Medical History and Physical Examination

Because osteogenesis imperfecta is often inherited, your doctor will discuss family
medical history in addition to your child's medical history. Your doctor will also
complete a thorough physical examination that includes checking your child's eyes
and teeth.

Tests

X-rays. X-rays will provide your doctor with clear images of your child's bones, showing
fractures as well as malformations of bone.

Laboratory tests. Your doctor may take blood or tissue samples for genetic testing. In many cases,
these tests are able to identify the mutation, particularly if the parent's mutation
is also known.

Ultrasound. Ultrasound can often detect severe cases of osteogenesis imperfecta during pregnancy.

While there is no cure for osteogenesis imperfecta, there are ways to improve a child's
quality of life. Treatment is individualized and depends on the severity of the disease
and the age of the patient. Care is provided by a team of healthcare professionals,
including several types of doctors, a physical therapist, a nurse-clinician, and a
social worker. Support from a social worker or psychologist is very helpful for both
the child and the family, and often becomes even more important during adolescence.

Nonsurgical Treatment

In most cases, treatment is nonsurgical.

Medication. Medical bisphosphonates, given to the child either by mouth or intravenously, slow
down bone resorption. In children with more severe osteogenesis imperfecta, bisphosphonate
treatment often reduces the number of fractures and bone pain. These medications must
be administered by properly trained doctors and require close monitoring.

Immobilization. Casting, bracing, or splinting fractures is necessary to keep the bones still and
in line so that healing can occur.

Exercise. After a fracture, movement and weight bearing are encouraged as soon as the bone
has healed. Specific exercises will increase mobility and decrease the risk of future
fractures.

Low-impact exercise, such as swimming and walking, can help strengthen bones and the
muscles that support them. Exercise is part of a healthy lifestyle for every child.

Surgical Treatment

Surgery may be recommended in cases of:

Repeated fractures of the same bone

Fractures that do not heal properly

Bone deformity, such as scoliosis

This 14-year-old boy with osteogenesis imperfecta has scoliosis. Scoliosis is a sideways
curve of the spine. Instead of a straight line down the middle of the back, this spine
has two curves.

Courtesy of Texas Scottish Rite Hospital for Children.

Rodding. Metal rods may be inserted in the long bones of the arms and legs to help reinforce
the bone, and subsequently lessen the number of fractures. Some rods are a fixed length
and must be replaced as a child grows. Other rods are designed like telescopes, and
they expand as a child's bones grow. There are, however, other complications that
may occur with telescoping rods. Do not hesitate to ask your orthopaedic surgeon about
both rodding options.

Spinal fusion for scoliosis. Although bracing is the usual treatment for scoliosis, it is not often effective
in children with osteogenesis imperfecta because the ribs will become deformed from
the brace, without preventing the scoliosis from worsening. Spinal fusion, a surgery
in which the bones of the spine are realigned and fused together, may be recommended
when the scoliosis becomes severe.

Below are some tips developed by the Osteogenesis Imperfecta Foundation for taking
care of children with osteogenesis imperfecta. Most importantly, do not feel guilty
if your child breaks a bone. Children must grow and develop, and fractures will occur
no matter how careful you are.

Do not be afraid to touch or hold an infant with osteogenesis imperfecta, but be careful.
To lift an infant with osteogenesis imperfecta, spread your fingers apart and put
one hand between the legs and under the buttocks, and place the other hand behind
the shoulders, neck, and head.

Never lift a child with osteogenesis imperfecta by holding him or her under the armpits.

Do not pull on arms or legs or, in those with severe osteogenesis imperfecta, lift
the legs by the ankles to change a diaper.

Select an infant car seat that reclines. It should be easy to place or remove your
child in the seat. Consider padding the seat with foam and using a layer of foam between
your child and the harness.

Be sure your stroller is large enough to accommodate casts. Do not use a sling- or
umbrella-type stroller.

Follow your doctor's instructions carefully, especially with regard to cast care and
mobility exercises. Swimming and walking are often recommended as safe exercises.

Adults with OI should avoid activities such as smoking, drinking, and taking steroids
because they have a negative impact on bone density.

Increasing awareness of child abuse and a lack of awareness about osteogenesis imperfecta
may lead to inaccurate conclusions about a family situation. Always have a letter
from your family doctor and a copy of your child's medical records handy.

Reviewed by members of POSNA (Pediatric Orthopaedic Society of North America)

The Pediatric Orthopaedic Society of North America (POSNA) is a group of board eligible/board
certified orthopaedic surgeons who have specialized training in the care of children's
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herein. This information is provided as an educational service and is not intended
to serve as medical advice. Anyone seeking specific orthopaedic advice or assistance
should consult his or her orthopaedic surgeon, or locate one in your area through
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